Hi PrafullJain ,
I checked your play and found that this property is present in your chatGPTIntegrationLWC.js-meta.xml file. Not able to find it in your JS file though. Is this property really needed for this component to run as you are not using it anywhere? If not, I would recommend you remove it from the meta.xml file and try it again. This seems like a Salesforce Validation Error.
If this doesn't solve your issue and you think it is a Playground issue, please let me know and I will take a deep dive into your play.
Thanks
Lakshay